fix: cmake configure_file path

[marcfir]

Any reasosn for CMAKE_CURRENT_BINARY_DIR?

[gemini-code-assist]

Summary of Changes

Hello @marcfir, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request resolves a configuration issue within the CMake build system by adjusting the destination path for a generated header file. The change ensures that config.h is placed in the source tree's include directory rather than the build directory, which likely corrects the file's intended location and prevents potential build or inclusion problems.

Highlights

• CMake Configuration Path: The output path for the config.h file generated by the configure_file command in CMakeLists.txt has been updated. It now directs the output to ${CMAKE_CURRENT_SOURCE_DIR}/include/libethercat/config.h instead of ${CMAKE_CURRENT_BINARY_DIR}/include/libethercat/config.h.

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[gemini-code-assist]

Code Review

This pull request changes the output path for the generated config.h file from the CMake binary directory to the source directory. While this might seem to align with how settings.h is handled on the next line, it introduces a deviation from CMake best practices. Generating files into the source directory can cause issues with out-of-source builds and version control. My review comment explains why the original approach of using the binary directory is correct and suggests reverting the change.

[gemini-code-assist]

This change directs the generated config.h file into the source directory (CMAKE_CURRENT_SOURCE_DIR). This is generally considered bad practice in CMake as it pollutes the source tree with build artifacts. The original use of CMAKE_CURRENT_BINARY_DIR was correct because it places generated files in the build directory.

This is important for a few reasons:

• Out-of-source builds: It allows for clean separation of source code and build artifacts. You can have multiple build directories (e.g., for debug, release, different toolchains) from a single source tree without them interfering with each other.
• Version Control: It prevents generated files from being accidentally committed to your repository.

The original code followed these best practices. If the goal was to ensure config.h is installed, a better approach would be to add a specific install() rule for the file after it's generated in the binary directory, rather than changing its generation path.

I recommend reverting this change to adhere to standard CMake practices. The same principle also applies to settings.h on the next line, which should also ideally be generated into CMAKE_CURRENT_BINARY_DIR.

configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/cmake_config.h.in ${CMAKE_CURRENT_BINARY_DIR}/include/libethercat/config.h)